The sill of the window frame is often made of materials such as aluminium or Belgian hardstone. This may look very nice, but it leaves something to be desired when it comes to the insulating value.
With the adoption of the 2012 Building Decree, the requirements for energy consumption have been greatly tightened, which means that a component such as the undersill can also be reconsidered during construction.



Fibreglass is a very good insulator, which makes it the ideal material for use as an undersill. With the addition of an eccentric fleece, the fibreglass can be given any look you want, from wood to Belgian hardstone.

Klant specifieke producten



As an innovative technology company, Prince Fibre is improving and developing processes every day. In this way, we were constantly involved with the development of the sill with our customer in order to define and perfect the exact demand for the product.

Friendly cooperation ultimately resulted in the optimised fibreglass sill.

Klant specifieke producten



The collaborative development of a customer-specific product is of paramount importance at Prince Fibre. By jointly designing and creating a unique product, we as specialist companies achieve growth with and for each other.

Has this unique sill caught your interest in fibreglass?

We will be happy to discuss a customised product with you. Feel free to contact one of our specialists so that we can discuss the possibilities with you!


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